PEAK SHAVING WITH BATTERY STORAGE | VOGT CTE

Power connections and generators must be designed for maximum performance, even if this is only required rarely.

High peaks lead to:

• Higher connection and operating costs,
• Larger and more expensive generators,
• Increased wear and tear,
• A poorer efficiency.
  
  

Many consumers (e.g., motors, machines, and chargers) only require a lot of power for a short time, such as during startup.

Principle of Peak Shaving
A peak-shaving system typically consists of:

• A base load source (e.g., grid or fuel cell generator) and
• An energy storage system (e.g., battery or supercapacitor) and
• A control system (energy management).

The base load source provides a constant output.
In cases of short-term increased demand, the storage system supplies additional energy. After the peak, the storage system is recharged gradually.

Peak Shaving with a Fuel Cell Generator
Fuel cells operate most efficiently at constant loads.

• They work most efficiently under steady load,
• Respond slowly to rapid changes in power demand.
• Degrade faster with frequent load jumps.

Therefore, they are particularly well-suited for base load but less for short-term peak demands.

Typical system setup:
Fuel cell generator: provides the base load.

• A battery or supercapacitor addresses power peaks.
• The power electronics and control coordinate the interactions.

Operational flow:
Normal operation: The fuel cell provides a constant 30 kW, for example.

• The current demand is about 25–30 kW.
• The excess power can be used to slowly charge the battery.
• Power peak: A large consumer turns on.
• The power demand temporarily rises to 60 kW.
• The fuel cell remains at 30 kW.
• The battery supplies the missing 30 kW.
• The power peak is thus smoothed out.
• After the peak, demand drops back to 30 kW.
• The fuel cell slowly recharges the battery.
• The system operates smoothly again.

Advantages of Peak Shaving with Fuel Cells

• Smaller fuel cell is sufficient → lower costs.
• High efficiency due to operation in the optimal load range.
• Longer lifespan of the fuel cell.
• Lower grid connection power required.
• Quieter, stable, and calmer operation.

Comparison: without and with Peak Shaving
Without Peak Shaving:

• The fuel cell must be designed for maximum power output.
• There are many load jumps.
• Lower efficiency.
• Higher investment and operating costs incurred.

With Peak Shaving:

• The fuel cell operates evenly.
• The storage system takes over the peaks.
• Higher efficiency.

The result is an economical and resource-friendly operation. In peak shaving with a fuel cell, the fuel cell handles the base load while a storage system manages the power peaks. This makes the energy system more efficient, durable, and economical.